A.T. Robertson Commentary Ephesians 1:8

"which he made to abound toward us in all wisdom and prudence," — Ephesians 1:8 (ASV)

According to the riches of his grace (κατα το πλουτος της χαριτος αυτου). A thoroughly Pauline phrase, riches of kindness (Romans 2:4), riches of glory (Colossians 1:27; Ephesians 3:16), riches of fulness of understanding (Colossians 2:7), riches of Christ (Ephesians 3:8), and in Eph 2:7 "the surpassing riches of grace."

Which (ης). Genitive attracted again to case of antecedent χαριτος.